Air control for white room



Feb. 6, 1968 G. K. RAIDER ETAL 3,367,257

AIR CONTROL FOR WHITE ROOM 4 Sheets-Sheet 1 Filed March 25, 1965 INVENTORS flea/:92 K, Fae der- Zdwamz/J 4285/8 Jaco M 110 Anse A/a/(QZaa/a I ATTORNEYS Feb. 6, 1968v a K. RAIDER ETAL 3,367,257

AIR CONTROL FOR WHITE ROOM 4 Sheets-Sheet Filed March 23, 1965 I NVENTOR-S ;Z ATTORNEYS Feb. 6, 1968 v G. K. RAIDER ETAL 3,357,257

AIR CONTROL FOR WHITE ROOM Filed March 23, 1965 4 Sheets-Sheet 5 z /%jg f 2 ATTORNEYS Feb. 6, 1968 G. K. RAlDER ETAL 3,367,257

AIR CONTROL FOR WHITE ROOM 4 Sheets-Sheet 1.

Filed March 25, 1965 6'90 Z'o m 0 Jae-ab mu fobnsen Yosfio NaKazaa/a 74 6%. ATTORNEYS United States Patent Office 3,367,257 Patented Feb. 6, 1968 3,367,257 AIR CONTROL FOR WHITE ROOM George K. Raider, Melrose Park, Edmund J. Little, Chicago, Jacob M. Johnsen, Wheaton, and Yoshio Nakazawa, Evanston, IlL, assignors to The Pyle-National Company, Chicago, 111., a corporation of New Jersey Filed Mar. 23, 1965, Ser. No. 441,984 7 Claims. (Cl. 9833) This invention relates generally to an air handling system suitable for ventilating, heating and air conditioning in which laminar flow air distribution is effected, thereby specifically adapting the system for use in a white room or a clean room facility or any areas wherein the conditions desired will keep turbulence to a minimum by means of throttling spaced plural air flow passages over areas co-extensive with the white room and on opposite sides thereof to provide a velocity traverse in the room within the limits of uniform laminar air flow.

In the provision of clean room facilities, or so-called white rooms supporting inertial guidance systems, it is necessary to provide ventilation which will not add anything that might contribute to the contamination of the room.

In accordance with the principles of the present invention, a clean room or white room is provided wherein two of the wall surfaces on opposite sides of the room, for example, the ceiling and the floor, are provided with spaced grille or panel units providing a plurality of separate air passages to permit complete control of air flow over the entire wall surface. The air control in all areas is such that supply air as well as return air can be throttled to 100% shut-off. Accordingly, the capacities for both supply air and return air can be established and balanced to within plus or minus of an optimum capacity, thereby meeting the requirements of uniform laminar air flow free of secondary air movement and at satisfactory displacements of velocity traverse through the entire room.

It is an object of the present invention, therefore, to provide an improved method and apparatus for effecting uniform laminar air flow in a clean room or a white room.

Yet another object of the present invention is to provide a unitary panel ceiling for a laminar flow air system wherein complete control of air is afforded over the entire ceiling area.

Yet another object of the present invention is to provide a uniform laminar air flow system wherein there is a reduction in the area of absolute filter requirements since the system of the invention can effectively use smaller filters located in any desired location in the air circuit.

Yet another object of the present invention is to provide a system wherein servicing of the filters can be accomplished outside of the clean area.

A further object of the present invention is to provide an air flow system for a clean room wherein there is reduced possibility of contaminated air leakage into the clean area.

A still further object of the present invention is to provide a laminar flow air system for a white room having the capability of concentrating higher air quantities where required.

Yet another object of the present invention is to provide a laminar flow air system for a clean room effecting a reduction in overall cost and accomplishing air distribution with improved efficiency.

Many other features, advantages and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description which follows and the accompanying sheets of drawings in which a preferred structural embodiment of a laminar flow air system for a white room as shown by way of illustrative example and in connection with which the methods of the present invention may be practiced.

On the drawings:

FIGURE 1 is a perspective view of a white room mock up embodying the features of the present invention;

FIGURE 2 is a schematic view illustrating the zone pattern established for a typical Wall or ceiling surface of a white room to be ventilated in accordance with the principles of the present invention;

FIGURE 3 is an air circuit diagram showing schematically the ventilating arrangement provided in the white room of FIGURE 1;

FIGURE 4 is an enlarged fragmentary view showing one of the grille modules in the floor construction of the white room of FIGURE 1;

FIGURE 5 is a cross-sectional view of the floor module frame illustrating how the grillework is supported;

FIGURE 6 is a somewhat schematic view illustrating in bottom plan view one of the air panel units in the ceiling of the white room of FIGURE 1;

FIGURE 7 is a cross-sectional view of one of the air panel units taken substantially on line VIIVII of FIG- URE 6; and

FIGURE 8 is a cross-sectional view taken generally on line VIII-VIII of FIGURE 7.

As shown on the drawings:

It will be appreciated that clean room facilities, or a so-called white room may take different architectural forms, and as such term is used herein reference is intended to refer to white rooms, clean rooms or any areas wherein the conditions desired will keep turbulence to a minimum. Accordingly, the mock up of a clean room or white room illustrated herein will exemplify the application of the principles of the present invention. Thus, as shown in FIGURE 1 and schematically in FIGURE 3, there is a white room R located in an architectural structure having a ceiling 10' and a floor 11, as well as side walls 12. In this particular construction, one of the side walls 12 is formed of hinged glass doors 12a, thereby affording ready access into the interior of the room for placing or removing equipment and also affording visual observation of the operating conditions existing within the room during the use thereof.

In accordance with the principles of the present invention, two oppositely disposed wall surfaces of the room R are provided with separate spaced valve controlled air passages by means of which the velocity traverse across the room R may be closely controlled and wherein the supply air as well as the return air can be throttled to shut-off in order to establish uniform laminar air flow.

As used in this disclosure, the term ventilating system is broadly applicable to heating, ventilating or air conditioning apparatus. In this particular embodiment, the oppositely disposed wall surfaces are provided in association with the ceiling 10 and the floor 11.

First of all, the oppositely disposed wall surfaces are divided into a plurality of modules. A typical distribution pattern is illustrated in FIGURE 2 wherein a wall surface area is shown divided into a grid pattern containing four modules 13 on each respective side. As applied to the floor area of the room R, the room is provided with a plurality of grid modules forming a floor frame (FIG- URES 4 and 5) shown generally at 14 and more specifically comprising frame members 16 carried on the floor 10, as well as bracket members 17 which prescribe side wall surfaces 18 for each respective grid module 13.

The bracket members 17 carry a support strip 19 at the upper extremity thereof on which is positioned a reversible I-bar grating 20 made of anodized aluminum. The I-bar grating 20 is supplied in the form of panel units so that a typical panel of I-bar grating 20 will correspond in size to the module 13.

Supported by the bracket construction 17 between the grille afforded by the I-bar grating 20 on the floor 10, is a control plate 21 provided for each respective module 13.

Each control plate 21 is characterized by the formation therein of a rectangular array of spaced elongated slots. The row of slots is bounded on opposite sides by a track member 22 fastened in firm assembly to the plate member 21, thereby to slidably support and guide a correspondingly slotted valve plate 23 fianged on its opposite ends as at 24 to facilitate manipulation thereof. The slots in the valve plate 23 are shown at 26 and it will be understood that sliding movement of the valve plate 23 on the control plate 21 will adjustably vary the size of the slot openings between a full open position and a 100% shut-off condition.

A screw 27 is carried by the control plate and passes through a slot 28 formed in the valve plate 23. Accordingly, the valve plate 23 may be locked in any adjusted position by tightening the screw 27 after the valve plate has been correspondingly adjusted.

Referring further to FIGURE 5, it will be noted that the grid modules 13 form together with the floor 10 a fioor plenum chamber identified at 29. The floor plenum chamber 29 operates as a return plenum and as shown in FIGURE 3, is connected to a return conduit 30 coupled as at 31 to a blower 32. The blower 32 is not only arranged to take a suction on the return air conduit 30, but also has a separate fresh air inlet as at 33 (see arrow of FIGURE 3).

In accordance with the principles of the present invention, absolute filter requirements are reduced and in this connection, it should be noticed that the complete filtering operation for effective white room performance can be carried on outside of the clean room area. Thus, the blower 32 may discharge through a filtering apparatus constituting a filtering housing 34 having a removable filter element 36. The clean filtered air is then discharged after leaving the filter housing 34 through a discharge conduit 37 and is supplied to a ceiling plenum shown in FIGURE 3 at 38.

As referred to in connection with FIGURE 2, the ceiling area is also divided up into a plurality of modules preferably corresponding or approximating the plurality of modules in the floor area. Thus, there is provided a T-bar suspension system which consists of a T-bar frame 40 spaced below the level of the ceiling 10 and carried thereby through the utilization of studs 41 and suspension wires 42 connected to the T-bar hangers as at 43 (FIGURE 8).

A plurality of panel units shown generally at 44 in FIGURE 6 are carried in the frame of the T-bar suspension system. Thus, each panel unit 44 comprises an upper plate 46, a side frame 47 and a bottom diffusion plate 48. Each adjacent pair of panel units 44 are separated from one another by means of neoprene sponge rubber gaskets 49 (FIGURE 7).

The upper plate 46 has air openings formed therein 50 through which air flows from the main ceiling plenum chamber 38 into each individual plenum chamber 51 formed by each respective panel unit 44.

Beneath each opening 50 and connected to the upper plate 46 by means of anodized aluminum sheet metal screws 52, are V-shaped perforated trough members 53. The openings formed in the trough members extend over the entire area thereof and are indicated at 54. The trough members, of course, operate to diffuse the air throughout the plenum chamber 51. The bottom plate 48 is also formed with a plurality of openings 56 spaced uniformly over the entire area and providing an open area ranging from to 90%, thereby to diffuse air by pressure displacement and in a substantially drafbfree fashion into the white room R.

A neoprene sponge rubber gasket 57 is interposed between the side frame 47 and the lower plate 48 and the parts are held in assembly with one another by means of a quarter turn lock fastener 58, a plurality of which may be provided along each longitudinal side of a panel unit 44.

In order to control the flow of air through the panel unit 44, a flanged valve plate 60 is carried on the end of a threaded adjustment screw 61 which in turn is supported on the upper plate 46 by means of a retaining bracket 62. The adjusting screw has a head 63 slotted to cooperate with a tool such as a screwdriver and the particular adjustment selected by actuation of the screw 61 may be locked by means of a winged lock nut 64.

To stabilize the valve plate, plural springs 66 are provided having bowed center portions connected to the valve plate 60 and end portions which ride against the upper plate 46. Thus, the valve plate is biased away from the openings and the adjustment screw 61 can be tightened to draw the valve plate towards a fully closed position so that the air flow through the panel unit 44 may be throttled to 100% shut-off, if desired.

In order to afford access to the adjustment screw 63, each lower plate 43 is provided with an opening 67 closed by a removable button plug 68. By removing the button plug 68, a screwdriver may be inserted through the hole and in engagement with the head 63, thereby to adjust the valve plate 60.

A neoprene sponge rubber gasket 70 is also interposed between the V-shaped trough members 53 and the upper plate 46.

In order to minimize introduction of foreign particles into the system, it is contemplated by the present invention that the entire panel Construction will be suitably constructed to be non-corrosive. For example, it may be of an aluminum construction and all of the joints gasketed with continuous neoprene sponge rubber, although the panels may be constructed of ferrous, non-ferrous or plastic material. If ferrous material, the panels 44 are supplied finished with a 1 to 1 /2 mils thickness standard T baked white epoxy enamel with a sheen of plus or minus 5 on a Gardner Gloss Meter. The panels are finished in such a manner so that no raw material will be exposed to the stream of ventilating air flowing into the white room.

The drawings show a table T presenting a typical work surface in a clean room facility. In operation, clean filtered air is supplied to the plenum chamber 38 and the air flows into the individual plenum chambers 51 through the valve controlled openings 50 and the perforated troughs 53. The air is then diffused by pressure displacement through the diffusion plate or lower plate 48 into the white room and flows in the direction of the arrows (FIGURE 3) downwardly to the grille modules 13. Since the panel modules 44 and the grille modules 13 correspond in approximate number and placement, the entire system can be balanced to meet the requirements of uniform laminar air flow, i.e., air discharged through the diffusion plate is positive across the entire surface and there is no aspirating of secondary air to the area between the upper plate 46 and the lower plate 48.

The velocity traverse across the room R is substantially uniform and may be selectively varied in the event it is necessary to concentrate a higher air quantity in a particular location.

If a smoke test were performed by placing a smoke bomb on the table T, the smoke virtually falls off of the edge of the table and passes straight downwardly through the return air plenum 29. Thus, it is possible to maintain an optimum air velocity at a selected minimum such as 25 f.p.m. at the working level of the table, while maintaining a uniform laminar air flow throughout the room.

Although minor modifications might be suggested by those versed in the art, it should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art.

We claim as our invention:

1. In combination:

means forming a white room having a floor,

a ceiling and side walls,

a T-bar suspension on said ceiling forming a frame below the level of said ceiling,

a plurality of unitary panel units in said frame,

each panel unit comprising upper and lower panel members spaced from one another and together with side panel members forming an outlet plenum chamber,

said upper panel member having an opening formed therein for admitting air from the space above said panel units into the interior of the outlet panel unit,

a perforated trough carried by said upper panel member and positioned below each said opening, a valve plate carried by said upper panel member and positioned above said opening,

valve adjustment means extending between said troughs for adjusting said valve plate relative to said opensaid lower panel member having a plurality of diffusion passages formed therein for diffusing air out of the outlet panel unit and into the white room,

a corresponding plurality of grid modules forming a floor frame above the level of said floor and together with the floor forming a return plenum,

each module comprising a control plate having a valve opening therein, a valve on said valve plate for adjustably opening and closing said opening to return air from the white room into the return plenum,

and a grid member above said control plate forming a support surface, whereby supply air as well as return air can be throttled to 100% shut-off and the system can be balanced to produce uniform laminar air flow through the white room.

2. In the combination of claim 1:

said unitary panel units being finished with a coating having a sheen of plus or minus 5 on a Gardner Gloss Meter, thereby to minimize introduction of contaminants into the white room.

3. In the combination of claim 1, air supply means located outside of said clean room and connected to the space above said panel units and to said return plenum for supplying ventilating air to said clean room.

4. In the combination of claim 3, said air supply means including filtering means outside of said clean room including a removable filter element to facilitate replacement of the filter element remote from the clean room.

5. In the combination of claim 1, said panel units being coated to minimize contamination.

6. In the combination of claim 5, said grid modules being made of anodized aluminum to minimize contamination.

7. In the combination of claim 6, said grid modules comprising I bar grating.

References Cited UNITED STATES PATENTS 2,610,567 9/1952 Davis 98-33 3,252,400 5/1966 Madl 98-33 X MEYER PERLIN, Primary Examiner. 

1. IN COMBINATION: MEANS FORMING A WHITE ROOM HAVING A FLOOR, A CEILING AND SIDE WALLS, A T-BAR SUSPENSION ON SAID CEILING FORMING A FRAME BELOW THE LEVEL OF SAID CEILING, A PLURALITY OF UNITARY PANEL UNITS IN SAID FRAME, EACH PANEL UNIT COMPRISING UPPER AND LOWER PANEL MEMBERS SPACED FROM ONE ANOTHER AND TOGETHER WITH SIDE PANEL MEMBERS FORMING AN OUTLET PLENUM CHAMBER, SAID UPPER PANEL MEMBER HAVING AN OPENING FORMED THEREIN FOR ADMITTING AIR FROM THE SPACE ABOVE SAID PANEL UNITS INTO THE INTERIOR OF THE OUTLET PANEL UNIT, A PERFORATED TROUGH CARRIED BY SAID UPPER PANEL MEMBER AND POSITIONED BELOW EACH SAID OPENING, A VALVE PLATE CARRIED BY SAID UPPER PANEL MEMBER AND POSITIONED ABOVE SAID OPENING, VALVE ADJUSTMENT MEANS EXTENDING BETWEEN SAID TROUGHS FOR ADJUSTING SAID VALVE PLATE RELATIVE TO SAID OPENING, SAID LOWER PANEL MEMBER HAVING A PLURALITY OF DIFFUSION PASSAGES FORMED THEREIN FOR DIFFUSING AIR OUT OF THE OUTLET PANEL UNIT AND INTO THE WHILE ROOM, A CORRESPONDING PLURALITY OF GRID MODULES FORMING A FLOOR FRAME ABOVE THE LEVEL OF SAID FLOOR AND TOGETHER WITH THE FLOOR FORMING A RETURN PLENUM, EACH MODULE COMPRISING A CONTROL PLATE HAVING A VALVE OPENING THEREIN, A VALVE ON SAID VALVE PLATE FOR ADJUSTABLY OPENING AND CLOSING SAID OPENING TO RETURN AIR FROM THE WHITE ROOM INTO THE RETURN PLENUM, AND A GRID MEMBER ABOVE SAID CONTROL PLATE FORMING A SUPPORT SURFACE, WHEREBY SUPPLY AIR AS WELL AS RETURN AIR CAN BE THROTTLED TO 100% SHUT-OFF AND THE SYSTEM CAN BE BALANCED TO PRODUCE UNIFORM LAMINAR AIR FLOW THROUGH THE WHITE ROOM. 